<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
        .container {}

        .container .cart {
            width: 300px;
            margin: auto;
        }

        .container .title {
            background-color: lightblue;
            height: 40px;
            line-height: 40px;
            text-align: center;
            /*color: #fff;*/
        }

        .container .total {
            background-color: #FFCE46;
            height: 50px;
            line-height: 50px;
            text-align: right;
        }

        .container .total button {
            margin: 0 10px;
            background-color: #DC4C40;
            height: 35px;
            width: 80px;
            border: 0;
        }

        .container .total span {
            color: red;
            font-weight: bold;
        }

        .container .item {
            height: 55px;
            line-height: 55px;
            position: relative;
            border-top: 1px solid #ADD8E6;
        }

        .container .item img {
            width: 45px;
            height: 45px;
            margin: 5px;
        }

        .container .item .name {
            position: absolute;
            width: 90px;
            top: 0;
            left: 55px;
            font-size: 16px;
        }

        .container .item .change {
            width: 100px;
            position: absolute;
            top: 0;
            right: 50px;
        }

        .container .item .change a {
            font-size: 20px;
            width: 30px;
            text-decoration: none;
            background-color: lightgray;
            vertical-align: middle;
        }

        .container .item .change .num {
            width: 40px;
            height: 25px;
        }

        .container .item .del {
            position: absolute;
            top: 0;
            right: 0px;
            width: 40px;
            text-align: center;
            font-size: 40px;
            cursor: pointer;
            color: red;
        }

        .container .item .del:hover {
            background-color: orange;
        }
    </style>
</head>

<body>
    <div id="app">
        <div class="container">
            <my-cart></my-cart>
        </div>
    </div>
    <script type="text/javascript" src="js/vue.js"></script>
    <script type="text/javascript">
        var CartTitle = {
            props: ['uname'],
            template: `
        <div class="title">{{uname}}的商品</div>
      `
        }
        var CartList = {
            props: ['list'],
            template: `
        <div>
          <div class="item" v-for="item in list" :key="item.id">
            <img :src="item.img"/>
            <div class="name">{{item.name}}</div>
            <div class="change">
              <a href="" @click.prevent="sub(item.id)">－</a>
              <input type="text" class="num" :value="item.num" @blur="changeNum(item.id,$event)" />
              <a href="" @click.prevent="add(item.id)">＋</a>
            </div>
            <div class="del" @click="del(item.id)">×</div>
          </div>
        </div>
      `,
            methods: {
                changeNum(id,event) {
                    //上面传递的$event是代表元素本身，里面的$event.target.value存储的是值
                    // console.log(id,event);
                    this.$emit('change-num',{
                        id,
                        type: 'change',
                        newNum: event.target.value
                    })
                },
                sub(id) {
                    this.$emit('change-num',{
                        id,
                        type: 'sub'
                    })
                },
                add(id) {
                    this.$emit('change-num',{
                        id,
                        type: 'add'
                    })
                },
                del(id) {
                    this.$emit('change-num',{
                        id,
                        type: 'del'
                    })
                }
            }
        }
        var CartTotal = {
            props: ['list'],
            template: `
        <div class="total">
          <span>总价：{{totalPrice}}</span>
          <button>结算</button>
        </div>
      `,
            computed: {
                totalPrice() {
                    let total = 0;
                    this.list.forEach(item => {
                        total += item.price * item.num;
                    });
                    return total;
                }
            }
        }
        Vue.component('my-cart', {
            data() {
                return {
                    uname: '张三',
                    list: [{
                        id: 1,
                        name: 'TCL彩电',
                        price: 1000,
                        num: 1,
                        img: 'img/a.jpg'
                    }, {
                        id: 2,
                        name: '机顶盒',
                        price: 1000,
                        num: 1,
                        img: 'img/b.jpg'
                    }, {
                        id: 3,
                        name: '海尔冰箱',
                        price: 1000,
                        num: 1,
                        img: 'img/c.jpg'
                    }, {
                        id: 4,
                        name: '小米手机',
                        price: 1000,
                        num: 1,
                        img: 'img/d.jpg'
                    }, {
                        id: 5,
                        name: 'PPTV电视',
                        price: 1000,
                        num: 2,
                        img: 'img/e.jpg'
                    }]
                }
            },
            template: `
        <div class='cart'>
          <cart-title :uname="uname"></cart-title>
          <cart-list :list="list" @change-num="changeNum"></cart-list>
          <cart-total :list="list"></cart-total>
        </div>
      `,
            components: {
                'cart-title': CartTitle,
                'cart-list': CartList,
                'cart-total': CartTotal
            },
            methods: {
                changeNum(obj) {
                    if(obj.type == 'change') {
                        this.list.some(item => {
                            if(item.id == obj.id) {
                                item.num = obj.newNum;
                                return true;
                            }
                        })
                    }else if(obj.type == 'sub') {
                        this.list.some(item => {
                            if(item.id == obj.id) {
                                item.num--;
                                item.num = item.num < 0 ? 0 : item.num;
                                return true;
                            }
                        })
                    }else if(obj.type == 'add') {
                        this.list.some(item => {
                            if(item.id == obj.id) {
                                item.num++;
                                return true;
                            }
                        })
                    }else if(obj.type == 'del'){
                        // let index = this.list.findIndex(item => {
                        //     if(item.id == obj.id) {
                        //         return true;
                        //     }
                        // })
                        // this.list.splice(index,1)
                        //上面的方法可以使用filter简化为下面这一行
                        this.list = this.list.filter(item => item.id != obj.id)
                    }
                }
            }
        });
        var vm = new Vue({
            el: '#app',
            data: {

            }
        });
    </script>
</body>

</html>